1. Field
This disclosure relates to wireless energy transfer, methods, systems and apparati to accomplish such transfer, and applications.
2. Description of the Related Art
Energy or power may be transferred wirelessly using a variety of techniques as detailed, for example, in commonly owned U.S. patent application Ser. No. 12/789,611 published on Sep. 23, 2010 as U.S. Pat. Pub. No. 2010/0237709 and entitled “RESONATOR ARRAYS FOR WIRELESS ENERGY TRANSFER,” and U.S. patent application Ser. No. 12/722,050 published on Jul. 22, 2010 as U.S. Pat. Pub. No. 2010/0181843 and entitled “WIRELESS ENERGY TRANSFER FOR REFRIGERATOR APPLICATION” the contents of which are incorporated in their entirety as if fully set forth herein. Prior art wireless energy transfer systems have been limited by a variety of factors including concerns over user safety, low energy transfer efficiencies and restrictive physical proximity/alignment tolerances for the energy supply and sink components.
One particular challenge in wireless energy transfer is thermal management of the resonator structures. In some embodiments, especially in high power embodiments transferring 100 W of power or more, under some conditions there may be significant amounts of power dissipated in the resonator structures. The dissipation of power may lead to heating of components or parts of the resonator structure. In some embodiments the heating may be undesirable or lead to undesirable consequences. For example, the heating may affect the properties, parameters, performance, and the like of the components and materials of the resonator structures changing the parameters of wireless energy transfer or reducing the efficiency of wireless energy transfer. In some embodiments, thermal changes may lead to a runaway of the resonator parameters. For example, a rise in temperature may increase the resistance of an electrical conductor, resulting in more heat generation, resulting in higher resistance and so on.
In embodiments, traditional thermal management technologies and techniques may not be suitable or desirable for resonator structures. For example, active cooling methods, such as fans, add noise, are difficult to weather proof, and may add to the complexity to the electronic control of the system. Furthermore, the parameters of magnetic resonator structures and the wireless power transfer system may be affected by the presence of metallic objects in the vicinity of the resonators and thus traditional metal heat sinking methods that use traditional heat sink extrusions may themselves affect the properties of wireless power transfer more than the thermal effects.
Therefore a need exists for methods and designs for improved thermal management in resonator structures.